Simulation On Fluid Flow In Tundish With Different Flow Control Devices

Tundish is the most important device to remove inclusions in continuous casting process. In order to improve slab quality, a series of studies have been carried out to make the tundish metallurgy functioning better. The main measure is to set suitable flow control devices in tundish to extend the mean residence time, reduce dead volume, and promote inclusion removing, as a result to improve steel quality.Mathematical modeling and water modeling were used to study the structure optimization of one strand tundish. The structure and the flow control device were discussing by measuring the RTD curves, erosion velocity and the height of slag entrapment. Chose the best inner structure and flow control device.The results showed that concave base tundish was more favorable than the flat bottom tundish in delaying the begginning time of rotation, reducing the residual liquid steel, and improving the the yield of molten steel, and the results showed that the size of the concave base was the larger the better; Increasing the distance between the near wall and the long nozzle can not improve the flow pattern and reduce the erosion.The flow control devices could improve the liquid steel flow pattern, but the affects were different, only reasonable combinations could obtain the best results. The weir reduced the disturbance in injection zone, improved inclusions floating ratio; Dam can effectively change the application of molten steel flow path, eliminate the short circuit, promote the development of surface flow, and remove the inclusions the float; Gas curtain played the similar role to dam, but bubble floating promoting the inclusion floating; Turbulence inhibitor well slowed down the ladle wall injection flow, the liquid steel in the impact area mixture more uniform, which promoting inclusion and reducing the impact of floating dead zone. Without turbulence inhibitor in tundish, dam is better than the gas curtain; but the application of turbulence inhibitor will reduce the dam impact and increase the gas curtain effect, increasing the ability to float inclusions, so the best flow control device was weir and turbulence inhibitor and gas curtain combination.Industrial experiments shown that the inclusions larger than 30μm were removed, and 5~30μm small particles inclusions dispersed in tundish, tundish metallurgical results meet the requirements.